David P. Schmitt is a personality psychologist who founded the International Sexuality Description Project (ISDP). The ISDP is the largest-ever cross-cultural research study on sex and personality. Over 100 psychologists simultaneously administered an anonymous self-report survey to 17,837 individuals representing 56 different nations, 6 continents, 13 islands, and 30 languages. Direct assessments of people's personality traits and sexual behaviors have led to innovative tests of evolutionary psychology and social role theory. A second wave of the ISDP is currently underway and includes measures of subjective well-being, social dominance, sexual aggression, rape attitudes, HIV risk, and psychopathy.